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Seems bad goes with good

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  • #1

    Seems bad goes with good

    Ok, I had a good ride yesterday, but in the process a knock/rattle started in my new engine. Strange thing is that it starts around 3k and if I back off or really get on it it fades away. I'm pretty bummed, but I'm trying to come up with some sort of idea of what it could be. I get more noise when it's really gotten hot from sustained high speed running, and today it seems to be just barely there at all. Could this be a cam chain adjustment issue? I'm going to try the cam chain adjustment again, I'm assuming it is best done with the engine cold?

    Could the cam chain cause a noise like that as it gets hotter and increases in length? I'm guessing I need to get my old engine torn down and start rebuilding it. At least then I will know what I have, no surprises, I don't think I can take much more of this, and so far all the running engines I have found are going to cost $700 to over 1000 to get them here, which is just not worth it.
    Cy

    1980 XS1100G (Brutus) w/81H Engine
    Duplicolor Mirage Paint Job (Purple/Green)
    Vetter Windjammer IV
    Vetter hard bags & Trunk
    OEM Luggage Rack
    Jardine Spaghetti 4-2 exhaust system
    Spade Fuse Box
    Turn Signal Auto Cancel Mod
    750 FD Mod
    TC Spin on Oil Filter Adapter (temp removed)
    XJ1100 Front Footpegs
    XJ1100 Shocks

    I was always taught to respect my elders, but it keeps getting harder to find one.
    Tags: None
  • #2
    sounds like cam chain
    careful what you wish for.........you might get it

    Comment

    • #3
      My Special does that sometimes when it's hot. It might have something to do with the vac. advance if it only happens when cruising. Semi-recent thread...

      http://www.xs11.com/forum/showthread...hlight=advance
      2H7 (79)
      3H3

      "If it ain't broke, modify it"

      ☮

      Comment

      • #4
        Man, noises are hard to diagnose from on here. Usually.. it's either a rattle.. cam chain sound.. or a knock.. bearings.

        Are you leaking any oil out of either side cover? Does it sound like it's high in the motor, or down at the bottom?

        Tod
        Try your hardest to be the kind of person your dog thinks you are.

        You can live to be 100, as long as you give up everything that would make you want to live to be 100!

        Current bikes:
        '06 Suzuki DR650
        *'82 XJ1100 with the 1179 kit. "Mad Maxim"
        '82 XJ1100 Completely stock fixer-upper
        '82 XJ1100 Bagger fixer-upper
        '82 XJ1100 Motor/frame and lots of boxes of parts
        '82 XJ1100 Parts bike
        '81 XS1100 Special
        '81 YZ250
        '80 XS850 Special
        '80 XR100
        *Crashed/Totalled, still own

        Comment

        • #5
          There was a TSB about the vacuum advance causing a knock sound on some of the models. It occurs on mine at about 4500, and sounds like a defined engine knock and at times it is accompanied by a pinging sound.

          It has never gotten worse or changed. So that makes me think that its ok.
          Ich habe dich nicht gefragt.

          Comment

          • #6
            I was experiencing something like that and knew I was only running on three cyls. After some extreme throttle on and off it went away. Apparently it was crap in one of the carbs. I thought I had a bad connecting rod or burned out valve, since I discovered that my #4 exhaust flange nuts were about to fall off. Tightened them and ran it as described and the issue went away. Rode 125mi today without as much as a sneeze. Good luck.
            1980G Standard, Restored
            Kerker 4 - 1
            850 Rear End Mod
            2-21 Flashing LED Arrays on either side of license plate for Brake Light Assist, 1100 Lumen Cree Aux Lights,
            Progressive springs, Showa rear shocks
            Automatic CCT
            1980GH Special, Restored
            Stock Exhaust, New Handlebars, 1" Spacer in Fork Springs, Automatic CCT, Showa Rear Shocks
            '82 XJ1100 (Sold)
            Automatic CCT, RC Engineering 4 X 1 Exhaust, K&N Pods, #50 Pilot Jets, YICS Eliminator. Sorely missed.

            Comment

            • #7
              Cy,
              I was just going to suggest what Cobia mentioned...
              You might recheck the exhaust flange nuts...
              Those things will back off, and the exhaust pipe will rattle at certain rpms & vibrations... they'll make you think it's a lot more serious than it is sometimes...
              JAT.
              '82 XJ1100J Maxim (has been sold.)

              '79 F "Time Machine"... oh yeah, Baby.... (Sold back to Maximan)

              2011 Kaw Concours 14 ABS

              In the warden's words from Cool Hand Luke;
              "What we have here is a failure to communicate."

              Comment

              • #8
                I'd have to go with what Ivan said. That sounds exactly like the detonation problem that these engines have.

                TC has the TSB on this.

                It's only there between 3 & 4k when your just cruising right? If you give it throttle or let off it goes away?

                I've found that it is worse if you run Reg. gas, my bike runs like crap on premium so I run the mid grade (97 oct.) and that helps. If I run some seafoam in the fuel it seems to make it even better.

                It's, the knock, not harmful to the engine, but it shure is HARD to get used to.

                Comment

                • #9
                  Ivan-
                  There was a TSB about the vacuum advance causing a knock sound on some of the models. It occurs on mine at about 4500, and sounds like a defined engine knock and at times it is accompanied by a pinging sound.
                  +1
                  I had that on my SG.between 3000-4500rpms"ish"
                  It drove me nuts,but it is no big deal.
                  80 SG XS1100
                  14 Victory Cross Country

                  Comment

                  • #10
                    Here's that TSB I found it

                    Comment

                    • #11
                      Click on it and you can make it bigger

                      Comment

                      • #12
                        Tho' this probably isn't the problem, take a real close look at the heat shields below the footpegs. I had a noise/vibration a few years ago that sounded like the engine was about to explode at certain RPMs.

                        After many paranoid thoughts I found that a small crack had formed in the left heat shield. A small glop weld fixed the problem but I'm still surprised that such a small defect could produce such a loud, expensive sounding noise.

                        Luck,

                        Rob

                        Comment

                        • #13
                          Well, after some checking, and putting some premium gas in it (which turned out to be bad, ran like crap (would hardly run at all, I thought I was riding a harley)), so I drained the carbs and the tank and put fresh regular unleaded in it and checked the timing and found I was about 1 degree fast, so I reset it back about 4 degrees and it's a LOT better now.

                          When I read the TSB it described almost exactly what I was hearing, so rather than get rid of the advance (since I don't think the replacement unit is still available), I just retarded it a little, and it's much quieter (the cam chain adjuster thing seemed to have helped some too).

                          So, it's sounding pretty good now, so I am going to enjoy riding and listen to what it sounds like (and I'm thinking about what I can do to make the fairing stop being a megaphone for engine noises).

                          Thanks for all the advice and help, I think I've got it dialed in.
                          Cy

                          1980 XS1100G (Brutus) w/81H Engine
                          Duplicolor Mirage Paint Job (Purple/Green)
                          Vetter Windjammer IV
                          Vetter hard bags & Trunk
                          OEM Luggage Rack
                          Jardine Spaghetti 4-2 exhaust system
                          Spade Fuse Box
                          Turn Signal Auto Cancel Mod
                          750 FD Mod
                          TC Spin on Oil Filter Adapter (temp removed)
                          XJ1100 Front Footpegs
                          XJ1100 Shocks

                          I was always taught to respect my elders, but it keeps getting harder to find one.

                          Comment

                          • #14
                            Cy, like I said, the mid grade runs good and Seafoam helps too.

                            Premium makes 'em run like crap.

                            No, the replacement vac. adv. unit is no longer available. That sucks.

                            Glad we could help.

                            With the fairing you will hear every little noise. The old girl has quite a few.

                            You'll learn 'em.

                            Comment

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